121205321 has 2 divisors, whose sum is σ = 121205322. Its totient is φ = 121205320.

The previous prime is 121205317. The next prime is 121205323. The reversal of 121205321 is 123502121.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 108388921 + 12816400 = 10411^2 + 3580^2 .

It is a cyclic number.

It is not a de Polignac number, because 121205321 - 2² = 121205317 is a prime.

Together with 121205323, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121205321.

It is not a weakly prime, because it can be changed into another prime (121205323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60602660 + 60602661.

It is an arithmetic number, because the mean of its divisors is an integer number (60602661).

Almost surely, 2^121205321 is an apocalyptic number.

It is an amenable number.

121205321 is a deficient number, since it is larger than the sum of its proper divisors (1).

121205321 is an equidigital number, since it uses as much as digits as its factorization.

121205321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 121205321 is about 11009.3288169625. The cubic root of 121205321 is about 494.8883481130. Note that the first 3 decimals are identical.

Adding to 121205321 its reverse (123502121), we get a palindrome (244707442).

The spelling of 121205321 in words is "one hundred twenty-one million, two hundred five thousand, three hundred twenty-one".